Sakai, 1935
Carapace very much elongated pyriform, smooth and naked except for some curled hairs scattered on the branchial, gastric and frontal regions. A remarkable constriction behind the orbital region and also behind the hepatic region.
Rostrum very much elongated and consists of two acute slender spines, which are in close contact throughout, and divergent at the apex; the outer borders appear minutely serrated under the lens. Supraorbital hood very prominent, each of its anterior and posterior angles ends in a sharp spine, the former directed obliquely outward and forward, the latter outward and backward.
Hepatic protuberances terminate laterally in a very long and acute spine. Branchial and cardiac regions are strongly convex and are rounded. There are three spinules in the middle line of the carapace, each at the centre of the gastric, cardiac and intestinal regions respectively.
Basal antennal segment very broad, armed with two teeth on outer border, the one in the middle, the other on the distal end and is very sharp and large, visible from above on each side of the rostrum.
Pterygostomial region armed with five or six tubercles arranged in a line obliquely outwards, which leads anteriorly to the well defined anterior buccal corner; sub-hepatic region is also armed with two or three spinules.
Chelipeds very long in full grown males; merus and carpus are granulated, the granules arranged somewhat in longitudinal lines, especially near the anterior and posterior borders. Palm laterally compressed, very smooth, upper ridge sharp. Movable finger longer than the fixed finger, both are armed with several indistinct denticles on the inner edge, and a narrow hiatus is left between the fingers.
Of ambulatory legs, the first pair is longest, almost reaching to the base of the fixed finger of the cheliped, the following pairs decrease in length rapidly in order. All dactyli are curved and very sharp. The terminal abdominal segment of the male is narrow and sub-triangular. (Sakai, 1935)
Type locality: between Ito and Hatsushima, Sagami Bay, Japan.
Range: Japan - between Ito and Hatsushima and Simoda (Sakai, 1935), Sagami Bay (Sakai, 1965b), between Ito and Hatsushima, Simoda and Sagami Bay (Sakai, 1976a), Shiono-misaki (Takeda, 1979a); 50-120 m.